- #1

Eugen

- 22

- 1

Here's the problem:

Suppose we orient the x-axis of a two-dimensional coordinate system along the beach at Waikiki. Waves approaching the beach have a velocity relative to thTe shore given by v = (1.3 m/s)y. Surfers move more rapidly than the waves, but at an angle to the beach. The angle is chosen so that the surfers approach the shore with the same speed as the waves. (a) If a surfer has a speed of 7.2 m/s relative to the water, what is her direction of motion relative to the positive x axis? (b) What is the surfer’s velocity relative to the wave? (c) If the surfer’s speed is increased, will the angle in part (a) increase or decrease? Explain.

The problem says that "the surfers approach the shore with the same speed as the waves". I take this to mean "the surfers velocity relative to the shore is the same as the waves velocity relative to the shore: 1.4 m/s". I think that's impossible because the surfers velocity relative to the shore is the waves velocity relative to the shore (1.4 m/s) + the surfers velocity relative to the water (7.2 m/s). Not matter what the angle of the surfers motion is, their speed relative to the shore will be much larger than 1.4 m/s.

Am I missing something?